U1064

DTC Troubleshooting: U1064

DTC U1064:

Seat Heater Control Unit Lost Communication With Climate Control unit

NOTE:

- If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.
- The seat heater control unit does not turn on the seat heater until the seat core temperature is 85 degrees or less. Make sure the seat core temperature is below 85 degrees before troubleshooting.

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0), and then back to ON (II).

3. Wait for at least 6 seconds.

4. Check for DTCs with the HDS.

Is DTC U1064 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the system is OK at this time. Check for loose or poor connections between the seat heater control unit and the climate control unit.

5. From the BODY ELECTRICAL SYSTEM SELECT menu, select B-CAN CONTROL UNITS INFORMATION, and then select CHECK CONNECTED CONTROL UNITS.

Is the seat heater control unit detected?

YES -

Go to step 9.

NO -

Go to step 6.

6. Measure the voltage between body ground and climate control unit connector A (36P) terminal No. 18.





Is there battery voltage?

YES -

Go to step 8.

NO -

Go to step 7.

7. Check the No. 36 (10 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?

YES -

Repair an open or high resistance in the No. 36 (10 A) fuse circuit.

NO -

Replace the fuse. If the fuse blows again, repair a short to ground in the No. 36 (10 A) fuse circuit.

8. Measure the voltage between body ground and climate control unit connector A (36P) terminal No. 36.





Is there less than 0.2 V

YES -

Go to step 9.

NO -

Repair an open or high resistance in the ground wire or poor ground (G403).

9. Turn the ignition switch to LOCK (0).

10. Disconnect the seat heater control unit 14P connector.

11. Disconnect the climate control unit connector A (36P).

12. Check for continuity between seat heater control unit 14P connector terminal No. 12 and No. 13 and climate control unit connector A (36P) terminal No. 1 and No. 19, respectively.





Is there continuity?

YES -

Replace the climate control unit Climate Control Unit Removal/Installation.

NO -

An open or poor connection in the B-CAN wire between the seat heater control unit and the climate control unit.